Appointment is one of a number of posts announced in a reshuffle of top roles in the Northern Ireland Civil Service

Northern Ireland Assembly building at Stormont. Photo: PA

Sue Gray, the Cabinet Office’s head of propriety and ethics who has been called one of the country’s most powerful civil servants, is to move to be permanent secretary of the Northern Ireland Department of Finance.

The surprise move was announced by the Northern Ireland Executive this afternoon. Gray will move from her post as director general of propriety and ethics and head of private offices group in the Cabinet Office to take up the position. She will replace Hugh Widdis, who has been undertaking the role in a temporary capacity and will return to his position as departmental solicitor and head of the Government Legal Service in Northern Ireland.

Gray has held a key role in the Cabinet Office since joining the department in the late 1990s, advising departments on standards and ethics issues, as well as corporate governance in public bodies. This has included leading investigations into ministerial misconduct, such as the recent probe that led to the resignation of Cabinet Office minister Damian Green, as well as investigations of civil servants and special advisors.

Gray's prominent role also saw her mentioned as the civil servant who advised Michael Gove, then education secretary, that emails sent in private email accounts on government business were exempt from Freedom of Information laws. This led to BBC Newsnight journalist Chris Cook to dub Gray “the most powerful person you've never heard of”, while former prime minister Gordon Brown wrote that: “Like Tony [Blair] before me and two prime ministers since, I was able to draw on the support of Sue Gray, a senior official in the Cabinet Office, who was always there with wise advice when – as all too regularly happened – mini-crises and crises befell.”

Before joining the Cabinet Office, Gray had worked in the departments of transport, health and work and pensions, and she also took a career break in the 1980s to run a pub in Newry, Northern Ireland.

Following the appointment, cabinet secretary Sir Jeremy Heywood tweeted his congratulations, stating she had been “a central part of life and leadership of the Cabinet Office for over 20 years”.

He added: “Thank you for your tireless, selfless and inspiring public service.”

Congratulations to Sue Gray on her appointment as Perm Sec of @dptfinance in NICS. A central part of life and leadership of @cabinetofficeuk for over 20 yrs. Thank you for your tireless, selfless and inspiring public service

Gray’s appointment follows a Northern Ireland Civil Service recruitment competition to identify possible candidates to fill permanent secretary vacancies across departments. The NICS announced today that there had been 42 applicants, of which 21 were listed for interview.

Other appointments made today include Noel Lavery, the current permanent secretary of the Department of Agriculture, Environment and Rural Affairs, moving to the Department for the Economy and replacing Dr Andrew McCormick, who has been appointed director general of international relations, reflecting the increasing challenges of Brexit.

Denis McMahon, who is currently deputy secretary of the work and inclusion group in the Department for Communities, will replace Lavery.

Gray and McMahon will take up their new posts over the next couple of months, and will be paid from £114,047 to £133,327. Gray is currently paid between £110,000 and £114,999.

The recruitment process for perm sec candidates has also created a “merit list” for future positions, which will remain live until the end of March 2019. The Executive Office’s Katrina Godfrey and Invest NI’s Tracy Meharg are the next two successful candidates on the list for this competition, NICS announced.

The appointments come at a time when there is no power-sharing executive in Northern Ireland due to a dispute between the Democratic Unionist Party and Sinn Féin over the mishandling of a renewable-heating initiative.

David Sterling, head of the Northern Ireland Civil Service, told MPs earlier today that it was was “unacceptable” that the country had been without an executive for a year and that public services were suffering as a result.